First carnivorous fungus from Santonian Taimyr amber

Abstract

Mycelium from the Yantardakh Lagerstätte (Santonian of Taimyr) is reported. Its hyphae are arranged mostly parallel, weakly branched and septated. The clamp connections indicate the Basidiomycota affinity. Two types of outgrowths are formed on the mycelium, located perpendicular to the parent hypha: the former rather long and common; and the latter are short peg-shaped, formed with a lower frequency. Arthroconidia and large spherical structures, looking like exudate drops are observed upon hyphae. Hyphae rings similar to the trapping loops of extant Basidiomycota have been found. Altogether, these rings, numerous drops and peg-like hyphal outgrowths may be interpreted as this mycelium belongs to nematophagous fungus of Agaricomycetes. Thus, this is the first finding of mycelium putatively nematophagous Basidiomycota from the Cretaceous of North Asia, which also implies the presence of nematodes in the Taimyr amber forest.